1) Field of the Disclosure
The disclosure relates generally to systems and methods for operating droop panels and flaps, and more specifically, to systems and methods for concurrently moving droop panels and trailing edge flaps of air vehicles using a pin joint linkage system.
2) Description of Related Art
The wings of high-speed transport air vehicles, such as aircraft, typically include various movable surfaces or devices to provide aircraft control and/or to configure the aircraft for low speed operations, such as aircraft takeoff and landing. Such movable surfaces or devices may include, for example, leading edge devices, such as flaps and slats, and trailing edge devices, such as droop panels or spoilers, trailing edge flaps, and ailerons. These movable surfaces or devices are typically movable between a stowed position and a variety of deployed or extended positions, depending upon the particular flight condition of the aircraft. For example, during the cruise mode of the aircraft, these movable surfaces and devices may be stowed or retracted to reduce aircraft drag, and during the takeoff or landing modes of the aircraft, these movable surfaces and devices may be deployed or extended to increase aircraft lift.
In the design and manufacture of high-speed transport air vehicles, such as aircraft, it is desirable to improve low speed performance of the aircraft by decreasing the minimum takeoff and landing distances of the aircraft. Improved efficiency and performance of aircraft takeoff and landing may result in reduced aircraft fuel consumption, and in turn, may result in reduced aircraft fuel costs. It has been found that drooping or downwardly lowering the droop panels or spoilers of the aircraft wing during takeoff and landing may improve airflow proximate to the wing and to a deployed trailing edge flap, as compared to when the droop panels or spoilers are not drooped. Such improved airflow may improve the overall performance of the wing by increasing lift and/or decreasing drag.
Known systems and methods exist for operating droop panels or spoilers. One such known system and method uses an eccentric linkage mechanism, typically a circular disk fixed to a rotating axle, which is offset from the center of the circle. Such known eccentric linkage mechanism uses a hydraulic actuator to operate the droop panel or spoiler separately from trailing edge flap.
However, such eccentric linkage mechanisms may be structurally heavy in weight, which in turn, may result in increased structural weight to the aircraft wing and aircraft. Moreover, such eccentric linkage mechanisms may have complex joints with numerous parts, which may result in increased complexity with assembly, and in turn, may result in increased labor and assembly costs. Further, such eccentric linkage mechanisms may expand the connection area between links, which in turn, may result in decreased integration space in the aircraft wing for integration of one or more other aircraft systems, such as an electrical system, a mechanical system, a hydraulic system, or another aircraft system.
Another known system and method for operating droop panels or spoilers exists that uses a hydraulic actuator system to drive a droop panel or spoiler in both an upward direction and in a downward direction. However, on aircraft where aircraft evacuation slides may be required at the most inboard sides of the aircraft wings on overwing exits, evacuation slide requirements may affect or limit certain operational parameters of spoilers and flight control panels.
In addition, known droop panels or spoilers driven by hydraulic actuator systems may require the use of additional electro-mechanical actuators in order to meet aircraft roll capability requirements. However, such additional electro-mechanical actuators may increase system complexity and weight, and may result in increased installation and maintenance costs.
In addition, another known system and method for operating droop panels or spoilers exists that includes a deep (long) hinge flap system and that uses a mechanical straight linkage system to drive the droop panel or spoiler to a drooped position. However, such mechanical straight linkage system of the deep hinge flap system may span a significant distance, e.g., six feet below the wing surface, and may thus add weight and complexity to the system, which in turn, may result in increased manufacturing and operation costs.
Accordingly, there is a need in the art for an improved system and method for operating a droop panel or spoiler of an air vehicle that provide advantages over known systems and methods.